Connecting member for a board for educational purposes and a board incorporating such a member



Sept. 27, 1966 w. B. GARDEN CONNECTING MEMBER FOR A BOARD FOR EDUCATIONAL PURPOSES AND A BOARD INCORPORAI'ING SUCH A MEMBER Filed April 5, 1964 United States Patent Ofltice 3,274,707 Patented Sept. 27, 1966 3,274 '707 CONNECTING MEMBER ron A BOARD non EDU- CATIONAL PURPOSES AND A BOARD INCUR- PORATING SUCH A MEMBER William Brownie Garden, Kilsyth, near Glasgow, Scotland, assignor to Wilson & Garden Limited, Glasgow, Scotland, a corporation of the United Kingdom of Great Britain and Northern Ireland Filed Apr. 3, 1964, Ser. No. 357,227 Claims priority, application Great Britain, Apr. 4, 1963, 13,312/63 Claims. (Cl. 35-62) This invention relates to an improved connecting member for a board for educational purposes and to a board incorporating such a member, the board being of the type comprising an endless band constituted by a flexible sheet of blackboard surfacing or other material capable of hearing indicia, the opposed ends of said sheet being interconnected by a connecting member and the sheet being entrained over top and bottom rollers carried by a frame presented by spaced uprights.

It has hitherto been known to use a hollow connecting member of substantially trapezoidal form in cross-section to interconnect the opposed ends of the sheet, one side of the member being formed with a longitudinally extending slot within which is located, as to be projecting therethrough, two blades, the edge portions of which, located outwith the member, are bifurcated and are secured to the opposed ends of the sheet which are to be interconnected, the blades being removable from the member only in the direction of the longitudinal length of the member. As will be appreciated the inwardly facing surface of the endless band which contacts with the rollers as the band is moved thereover presents portions of the blades which, being of a rigid material, such as metal, cause vibration with consequent noise when said portions of the blades pass over the rollers and the backing for the endless band.

It is the primary object of the present invention to provide a connecting member for the purpose hereinbefore indicated, and a board incorporating such a member or members, in which the above disadvantages are overcome when the board is in use.

A connecting member according to the present invention comprises a hollow bar of trapezoidal cross-section having a longitudinally extending slot formed in one side of the bar, longitudinally extending channels being so formed within the bar adjacent to the side walls of the bar on either side of the slot as to be open to the interior of the bar adjacent to the side thereof remote from the side in which the slot is formed whereby the end portions of the sheet associated with the opposed ends thereof to be interconnected may be so located within the slot, with said ends, which present substantially rigid members, positioned within the channels, that insertion and removal of said end portions of the sheet into and from the bar, respectively, in other than the longitudinal direction are prevented.

In a board, for educational purposes, of the type referred to, according to the invention the opposed ends of the flexible sheet of blackboard surfacing or other material capable of bearing indicia are interconnected by a connecting member as defined in the last preceding paragraph.

In order that the invention may be more clearly understood and more readily carried into effect the same will now be described with reference to the accompanying drawing in which FIG. 1 is an elevation view of one embodiment of a connecting member, according to the invention, interconnecting the opposed ends of the sheet, only the end portions of the sheet associated with said ends being shown, and FIG. 2 is a view in the direction of the arrow A of FIG. 1.

With reference to the drawing, 1 denotes generally a hollow bar of trapezoidal cross-section the bar 1 consisting of two parallel, spaced sides 2, 3- the side 2 being of narrower width than the side 3 and having formed therein a longitudinally extending slot 4, and two sides 5 which interconnect the longitudinally extending edges of the sides 2, 3 and which are mutually divergent in the direction from the side 2 towards the side 3, the sides 5 being equally inclined to the plane containing the side 2 and also, of course, to the plane containing the side 3. The sides 5 being inclined as indicated above facilitate the use of the connecting member as a handgrip by means of which the endless band may operatively be manually turned, the sides 5, or one of the sides 5, being if desired, embossed or otherwise formed for ease in performing this operation.

longitudinally extending plates 6 disposed parallel to and spaced from the sides 5 are mounted within the bar 1, one longitudinally extending edge of one of the plates 6 being attached to the longitudinally extending edge of the side 2 defining one edge of the slot 4 and one longitudinally extending edge of the other plate 6 being attached to the longitudinally extending edge of the side 2 defining the other edge of the slot 4. Each plate 6, together with the adjacent side 5, defines a channel 7 which is open to the interior of the bar 1 at the end therof remote from the side 2.

Longitudinally extending flanges 8 disposed co-planar with the side 2 of the bar 1 are each attached along one longitudinally extending edge thereof to one of the longitudinally extending edges of the side 2 attached to the sides 5, the flanges 8 being in contact with the outside surface 9 of the endless band 10 when the connecting member is in use.

The connecting member which is preferably metallic, may conveniently be formed by an extrusion process from a single strip of material, the strip of material being longitudinally bent at the junctions of the side 3 and the sides 5 through an obtuse angle, at the junctions of the sides 5 and the flanges 8 through the same obtuse angle, at the longitudinally extending edges of the flanges 8 where the strip of material is refiexly bent, and at the junctions of the side 2 and the plates 6 through an obtuse angle. The edges of the plates 6 remote from the side 2 are preferably constituted by reflex bends formed in the edge portions of the strip of material, as illustrated, thereby obviating or mitigating any risk of said edges causing chafing of the end portions 11 of the flexible sheet 10 constituting the endless band, which are operatively disposed in contact with said edges as is hereinafter described.

The connecting member may alternatively be consituted by a plurality of parts (not shown) and in particular the side 3, the sides 5 and the surfaces of the flanges 8 facing the side 3 may be formed of one strip of material and the plates 6, the side 2 and the surfaces of the flanges -8 facing away from the side 3 may be formed of a second strip of material, the two surfaces of each flange 8 being interconnected as :by spot welding or riveting. In this method of construction, as in the method described in the last preceding paragraph, the flanges 8 are twice the thickness of the sides 2, 3, 5 of the bar 1.

Plug pieces 12 may be provided, each plug piece 12 comprising a shank portion 13 and an end plate '14 the shank portion 13 when the connecting member is operatively in use, being disposed within the bar 1 and being secured between the plates '6 with the end plate 14 covering the end of the connecting member thereby to prevent unintentional axial movement of the bar '1 relative to the ends of the sheet 10 interconnected thereby.

In practice, the flexible sheet 10 which when the opposed ends thereof are interconnected constitutes the endless !band, is disposed around the top and bottom rollers of the board with the opposed ends thereof adjacent and the end portions ill of the sheet associated wit-h said ends thereof are interconnected by reflexly bending the end portions 11 and sliding the end portions 1 1 axially through the longitudinal slot 4 in the side 2 of the bar 1, which serves to interconnect the end portions '11 with rigid blades attached to the opposed ends of the end portions !11 being axially slid into the channels 7, the sheet 10 projecting from the slot 4 in opposite directions so that the surfaces of the flanges 8 facing away from the side 3 are in contact with the outside surface 9 of the sheet 10.

The flexible sheet 10 which constitutes, when the opposed ends thereof are interconnected, the endless band may be, and preferably is, formed of a plurality of subsheets disposed in end-to-end relationship, the adjacent ends of adjacent sub-sheets being interconnected, for example, by a connecting member or members, according to the invention, in the manner hereinbefore described and reference-s to the flexible sheet '10 are to be construed accordingly. In this case, where one of the sub-sheets becomes damaged it may be 'replaced without the need to replace all the sub-sheets constituting the flexible sheet 10 and, furthermore, since connecting members according to the invention may be used to interconnect all the sub-sheets of the plurality thereof the use of the connecting members as handgrips is facilitated.

T-he reflex bend in the end portion 11 of each sheet 10 in combination with the rigid blade 15 located within the associated channel '7 prevents removal of the end portion 11 from the bar 1 in other than the longitudinal direction. The removable plug pieces '12 are then inserted into the ends of the bar 1 to prevent unintentional axial movement of the bar 1 relative to the rigid blades 15.

What is claimed is:

'1. A connecting member for a board for educational purposes comprising a hollow bar of trapezoidal cross-section, a longitudinally extending slot formed in one side of the bar, and longitudinally extending channels so presented within said bar adjacent to the sides of said bar on either side of said slot as to be open to the interior of said bar adjacent to the side thereof [remote from said side in which said slot is formed whereby the end portions of the sheet associated with the opposed ends thereof to be interconnected may be so located within said slot, with said ends, which present substantially rigid members, positioned within said channels, that insertion and removal of said end portions of the sheet into and from the bar, respectively, in other than the longitudinal direction are prevented.

2. A connecting member according to claim 1 in which said hollow bar of trapezoidal cross-section consists of two parallel, spaced sides one of which is of narrower width .than the other and has formed therein said longitudinally extending slot, and two further sides which interconnect the longitudinally extending edges of said two parallel, spaced sides and which are mutually divergent in the direction from that side of said two parallel, spaced sides which is of narrower width towards the other of said two parallel, spaced sides.

3. A connecting member according to claim 2 in which at least one of said further sides is embossed thereby to facilitate the use of said connecting member as a handgrip for turning the endless band when the connecting member is operatively in use.

4. A connecting member according to claim 1 in which longitudinally extending plates, disposed parallel to and spaced from said further sides, are mounted within the bar, one longitudinally extending edge of one of said plates being attached to the longitudinally extending edge of said side in which said slot is formed, defining one edge of said slot and one longitudinally extending edge of the other plate being attached to the other longitudinally extending edge, of said side defining the other edge of said slot, each plate, together with the adjacent one of said further sides, defining one of said longitudinally extending channels which are open to the interior of said bar at the ends thereof remote from said side in which said slot is formed.

5. A connecting member according to claim 1 in which longitudinally extending flanges disposed coplanar with said side in which said slot is formed are each attached along one longitudinally extending edge thereof to one of the longitudinally extending edges of said side attached to said further sides, said flange-s being in contact with the outside surface of the endless band when the connecting member is in use.

6. A connecting member according to claim 5 formed by an extrusion process from a single strip of material, the strip of material having been longitudinally bent at the junctions of the side, disposed parallel to said side in which said slot is formed, and said further sides through an obtuse angle, at the junctions of said further sides and said flanges through the same obtuse angle, at the longitudinally extending edges of said flanges remote from said side in which said slot is formed, where the strip of material is reflexly bent, and at the junctions of said side, in which said slot is formed, and the plates through an obtuse angle.

7. A connecting member according to claim 6 in which the edges of said plates remote from said side in which said slot is formed are constituted by reflex bends formed in the edge portions of the strip of material.

8. A connecting member according to claim 5 in which the side disposed parallel to said side in which said slot is formed, said further sides and the surfaces of said flanges facing said side disposed parallel to said side in which said slot is formed have been formed of one strip of material and said plates, said side in which said slot is formed and the surfaces of said flanges facing away from said side disposed parallel to said side in which said slot is formed are formed of a second strip of material, the two surfaces of each flange having been interconnected as by spot welding or riveting.

9. A connecting member according to claim 1 in which plug pieces are provided, each plug piece comprising a shank portion and an end plate, the shank portion, when the connecting member is operatively in use, being disposed within said bar and being secured between said plates with said end plate covering the end of the connecting member thereby to prevent unintentional axial movement of said bar relative to the ends of sheet interconnected thereby.

10. A board, for educational purposes, of the type referred to in which the opposed ends of the flexible sheet of blackboard surfacing or other material capable of bearing indicia are interconnected by a connecting member according to claim 1.

EUGENE R. CAPOZIO, Primary Examiner. H. S. SKOGQUIST, Assistant Examiner. 

1. A CONNECTING MEMBER FOR A BOARD FOR EDUCATIONAL PURPOSES COMPRISING A HOLLOW BAR OF TRAPEZOIDAL CROSS-SECTION, A LONGITUDINALLY EXTENDING SLOT FORMED IN ONES SIDE OF THE BAR, AND LONGITUDINALLY EXTENDING CHANNELS SO PRESENTED WITHIN SAID BAR ADJACENT TO THE SIDES OF SAID BAR ON EITHER SIDE OF SAID SLOT AS TO BE OPEN TO THE INTERIOR OF SAID BAR ADJACENT TO THE SIDE THEREOF REMOTE FROM SAID SIDE IN WHICH SAID SLOT IS FORMED WHEREBY THE END PORTIONS OF THE SHEET ASSOCIATED WITH THE OPPOSED ENDS THEREOF TO BE INTERCONNECTED MAY BE SO LOCATED WITHIN SAID SLOT, WITH SAID ENDS, WHICH PRESENT SUBSTANTIALLY RIGID MEMBERS, POSITONED WITHIN SAID CHANNELS, THAT INSERTION AND REMOVAL OF SAID END PORTIONS OF THE SHEET INTO AND FROM THE BAR, RESPECTIVELY, IN OTHER THAN THE LONGITUDINAL DIRECTION ARE PREVENTED. 